Fungi play a crucial role in terrestrial Arctic ecosystems as symbionts of vascular plants and nutrient recyclers in soil, with many species persistently or temporarily inhabiting the phyllosphere of the vegetation.

In this study we apply high-throughput sequencing to investigate the mycobiome of 172 samples of fresh (current year) and aged (3 year old) needles of Picea glauca from three sites over a distance of 500 km in Alaska (USA). We analysed Illumina-generated ITS2 sequences to relate mycobiome data with phenotypic tree traits, measures of genetic variation and climate variables obtained from long-term monitoring of the sites.

Alpha-diversity declined with increasing environmental stress/climate harshness. Fungal communities differed in richness and taxonomic composition between sites, with a pronounced difference in the relative abundance of OTUs assigned to species of the rust genus Chrysomyxa, plant pathogens which seem to have been in an outbreak at two sites at the time of sampling.

Beside climate parameters, needle age was the second strongest explanatory variable of the mycobiome composition, whereas we found no effect of tree genetic variation, indicating that environmental and tree trait specific variables mainly determined individual white spruce mycobiomes at Alaska's treelines.

真菌在陆地北极生态系统中起着至关重要的作用，它是土壤中维管植物和养分循环器的共生体，许多物种持续或暂时栖息在植被的叶圈中。

在这项研究中，我们运用高通量测序研究的新（当年）和年龄（3岁）的针172个样本mycobiome云杉青冈超过500公里的阿拉斯加（美国）的距离三个站点。我们分析了Illumina生成的ITS2序列，将霉菌基因组数据与表型树的性状，遗传变异的量度和长期监测站点获得的气候变量联系起来。

随着环境压力/气候恶劣程度的增加，阿尔法多样性下降。站点之间的真菌群落的丰富度和分类学组成有所不同，分配给锈菌金孢属（Chrysomyxa）物种的OTU的相对丰度存在显着差异，在采样时，这两个站点似乎已爆发了植物病原体。

除气候参数外，针头年龄是霉菌生物组组成的第二个最强的解释变量，而我们发现树木遗传变异没有影响，表明环境和树木性状的特定变量主要决定了阿拉斯加树木线的单个白云杉分枝杆菌。